ESP32/components/u8g2/sys/sdl/common/u8x8_sdl_key.c

#ifndef NO_SDL
#include "SDL.h"
#endif

/* return ascii key value or -1 */
int u8g_sdl_get_key(void)
{
#ifndef NO_SDL

  SDL_Event event;
  /* https://wiki.libsdl.org/SDL_PollEvent */
  if ( SDL_PollEvent(&event) != 0 )
  {
    switch (event.type) 
    {
        case SDL_QUIT:
            exit(0);
            break;
        case SDL_KEYDOWN:
          switch( event.key.keysym.sym )
          {
            /*     /usr/include/SDL/SDL_keysym.h */
            /* /usr/include/SDL2/SDL_keycode.h */
            case SDLK_a: return 'a';
            case SDLK_b: return 'b';
            case SDLK_c: return 'c';
            case SDLK_d: return 'd';
            case SDLK_e: return 'e';
            case SDLK_f: return 'f';
            case SDLK_g: return 'g';
            case SDLK_h: return 'h';
            case SDLK_i: return 'i';
            case SDLK_j: return 'j';
            case SDLK_k: return 'k';
            case SDLK_l: return 'l';
            case SDLK_m: return 'm';
            case SDLK_n: return 'n';
            case SDLK_o: return 'o';
            case SDLK_p: return 'p';
            case SDLK_q: return 'q';
            case SDLK_r: return 'r';
            case SDLK_s: return 's';
            case SDLK_t: return 't';
            case SDLK_u: return 'u';
            case SDLK_v: return 'v';
            case SDLK_w: return 'w';
            case SDLK_x: return 'x';
            case SDLK_y: return 'y';
            case SDLK_z: return 'z';
            case SDLK_SPACE: return ' ';
            case SDLK_UP: return 273;
            case SDLK_DOWN: return 274;
            case SDLK_RIGHT: return 275;
            case SDLK_LEFT: return 276;
            case SDLK_PERIOD: return '.';
            
            default: return 0;
          }
    }
  }
#endif 
  return -1;
}